Does anyone know for sure whether this lens has been discontinued?
Sigma lists only the 50 EX, 105 EX and 180/2.8 on their website. B&H doesn't list it but Adorama does. Also, please correct the following assumptions:
<p>
1) This Sigma lens + Nikon 6T has a greater working distance than Canon's 180 at 1:1. According to Photozone data, the Canon has a close focusing distance from the film plane of 47 cm @ 1:1. Subtract from that the combined lens length (~19 cm), the camera depth (~4 cm for EOS?) and the barrel extension ( BE - unknown), you get a working distance of ~(24 - BE) cm. the Sigma + 6T has a working distance of ~(34 - BE) cm (= 1 m /2.9 diopters) from the front of the 6T minus the barrel extension. Since Canon's full barrel extesion is 1:1 and the Sigma's is 1:2, the difference in working distance is likely to be even more than 10 cm.
<p>
2) The Sigma is effectively only 1/3 stop slower than the Canon at 1:1. My understanding is that you lose the equivalent of 1 stop at 1:2 and 2 stops at 1:1. Thus the Canon f/3.5 at 1:1 would be an equivalent f/7.0. The Sigma f/5.6 becomes an f/8 because it doesn't lose a stop between 1:2 and 1:1 when you add the 6T.
<p>
Yes, I know the Canon is sharper and the build quality is worse (how bad is it?), but the Sigma + 6T option is $384. Also, I have an Elan IIE - anyone know if there are compatibility problems between these two? Compared to Sigma's new 105mm, the 180/5.6 costs about the same, has a greater working distance and includes a tripod mount (I think). Furthermore, the size and weight are about the same between the two Sigmas. Will the downsides (sharpness, build quality & compatibility) to this lens outweigh the upsides (working distance, cost and tripod mount) when used strictly for macro work? I know that only I can answer that after testing all options. However, in a reasonably large metropolis like Atlanta, nobody stocks any of these lenses. So, like Jeroen, I'd appreciate any first hand knowledge anyone may have. Thanks.
Sigma 180mm f5.6 Macro
in Nature
Posted
Does anyone know for sure whether this lens has been discontinued?
Sigma lists only the 50 EX, 105 EX and 180/2.8 on their website. B&H doesn't list it but Adorama does. Also, please correct the following assumptions:
<p>
1) This Sigma lens + Nikon 6T has a greater working distance than Canon's 180 at 1:1. According to Photozone data, the Canon has a close focusing distance from the film plane of 47 cm @ 1:1. Subtract from that the combined lens length (~19 cm), the camera depth (~4 cm for EOS?) and the barrel extension ( BE - unknown), you get a working distance of ~(24 - BE) cm. the Sigma + 6T has a working distance of ~(34 - BE) cm (= 1 m /2.9 diopters) from the front of the 6T minus the barrel extension. Since Canon's full barrel extesion is 1:1 and the Sigma's is 1:2, the difference in working distance is likely to be even more than 10 cm.
<p>
2) The Sigma is effectively only 1/3 stop slower than the Canon at 1:1. My understanding is that you lose the equivalent of 1 stop at 1:2 and 2 stops at 1:1. Thus the Canon f/3.5 at 1:1 would be an equivalent f/7.0. The Sigma f/5.6 becomes an f/8 because it doesn't lose a stop between 1:2 and 1:1 when you add the 6T.
<p>
Yes, I know the Canon is sharper and the build quality is worse (how bad is it?), but the Sigma + 6T option is $384. Also, I have an Elan IIE - anyone know if there are compatibility problems between these two? Compared to Sigma's new 105mm, the 180/5.6 costs about the same, has a greater working distance and includes a tripod mount (I think). Furthermore, the size and weight are about the same between the two Sigmas. Will the downsides (sharpness, build quality & compatibility) to this lens outweigh the upsides (working distance, cost and tripod mount) when used strictly for macro work? I know that only I can answer that after testing all options. However, in a reasonably large metropolis like Atlanta, nobody stocks any of these lenses. So, like Jeroen, I'd appreciate any first hand knowledge anyone may have. Thanks.